Which class of fire uses WATER as the primary extinguishing agent?

• A. Class B
• B. Class A
• C. Class D
• D. Class C

Answer: (B)

Water cools the fuel by absorbing heat, lowering the temperature of the combustion and preventing the fuel from reaching its ignition point. This cooling action makes it the primary extinguishing agent for fires involving ordinary combustibles like wood, paper, and textiles. For other fire types, water isn’t appropriate: flammable liquid fires can be spread by water, electrical fires pose shock risks (unless power is off or a non-conductive agent is used), and metal fires require specialized dry powders. So water is best suited for fires with ordinary combustibles.